A thermally stable ultra-hard material, a cutting element incorporating such thermally stable ultra-hard material, and methods for forming the same. A thermally stable ultra-hard diamond element is combined with a second ultra-hard material volume forming an assembly. One or more surfaces of the thermally stable diamond element that face the second diamond volume are coated with a coating prior to combining the thermally stable diamond element with the second diamond volume. The assembly is sintered at high pressure and high temperature to form PCD from the second diamond volume.